Based on your needs, I would have a B&W turnover ball system installed on your truck. This would allow easy removal of a bed mounted Gooseneck ball. There are a number of fifth wheel hitches that will mount utilizing the ball. Examples are, B&W Companion, Andersen Ultimate, and the Goose Box which is a pin box that mounts on the trailer.
On a 2006 truck, your other option is to install universal rails which might interfere with your camper usage. Virtually any hitch will work with the weight range you cited. Every hitch has its pros and cons, such as weight, cost, mounting method, hook up method, short bed adaptability, and towing comfort.